Evaluation of polyester, epoxy and acrylic resins for suitability in preparation of soil thin sections for in situ biological studies

Micromorphological investigations which aim to integrate both physical and biological features of soils are particularly demanding with respect to the quality of the thin sections produced for such studies. Rapid preparation of thin sections is also often desirable. The suitability of a range of resins for the rapid preparation of high-quality thin sections appropriate for biologically oriented studies was tested. Preparative procedures were investigated using four undisturbed soils (albic, calcic, humic, and argillic horizons) chosen to exhibit contrasting properties. Roots of sown Lolium perenne, their associated AM-mycorrhizas, and indigenous fungi and actinomycetes of the soils were used as indicators of the quality of preservation of biological material in sections of 15 mu m thickness. Crystic 17449 and Palatal P50-01 proved most suitable, producing durable sections in 2-3 weeks with excellent preservation of roots, microbes and inorganic features in all the soils tested.